104 national geographic • may 2016
that lasted from 1934 to 1967. Whipsaw changes. During that long
elk-reduction regime, park rangers shot 13,753 elk from the north-
ern herd, private hunters killed 41,400 when the animals migrated
out of the park, and almost 7,000 were trapped and shipped away to
forests and zoos elsewhere. In the late 1960s the park superintendent
and his chief biologist, influenced by the Leopold Report and some
fashionable new thinking in ecology, embraced a policy called nat-
ural regulation. But what were the limits of “natural” in the service
of “regulation”? Was it more natural to let elk starve than to hunt
them? Was it more natural to haze bison back into Yellowstone with
helicopters, trucks, and rangers on horseback than to ship them to
slaughter so that the meat could go to Native American tribes? Hard
to say. That fancy phrase “natural regulation” served to codify in two
words—but not solve—the paradox of the cultivated wild.
As for wolves, reintroducing them was a bold act of management
that did restore some “natural” conditions. But how far do those con-
ditions ramify?
Attitudes toward the wolf are more bitterly polarized and complex
than those around any other creature in Yellowstone. Beyond the
wolf-haters-versus-wolf-lovers tussle, scientists disagree about how
and to what degree wolves are reshaping the Yellowstone ecosystem.
Do they reduce reproductive success among elk simply by creating a
landscape of fear, wherein the great bulls and cows are too nervous
to eat and procreate? Have wolves killed enough elk to curtail elk
browsing on aspen and willow shoots? Has that reduced browsing
allowed aspen and willow stands in Yellowstone to recover and renew
themselves for the first time in decades? Has such aspen and willow
recovery enabled the return of beavers and songbirds? Or is reality a
little more intricate? Some scientists and wolf advocates tell this story
in happy, simplistic terms. “But it’s an unproven theory that gets undue
attention,” Middleton said, “in the quest to have wolves shine rainbows
out of their asses.”
Middleton is an improbable fit for the role of Wyoming elk ma-
ven: a South Carolina kid, a graduate of the Yale School of Forestry
and Environmental Studies, who came west nine years ago, having
landed work on a study of elk-wolf interactions commissioned by
Wyoming Game and Fish. After arriving in Cody to meet his new
collaborator, he admitted that he’d never seen a wolf or an elk. But
he learned fast, and he loved the mountains. He put GPS collars
on elk, clarifying poorly understood patterns in their movements
between summer and winter ranges. He collated similar data from
other researchers and made eye-opening digital maps. Look where
these animals go. “Most of Yellowstone’s elk,” he said later, “are not
in Yellowstone for most of the year.” They’re off the plateau, down
on winter range, where the snow isn’t so deep and the temperatures
aren’t so brutal, largely on private ranches. By this time Middleton
had a Ph.D. from the University of Wyoming and a postdoc position
back at Yale. His hair was long, his speech was slow and considered,
his brow scrinched when he pondered something carefully. Within
Great Migrations
As many as 25,000 elk
spend summers grazing in
the region’s high pastures,
but fewer than 5,000 stay
for the winter. The herds
shown at right make up
most of the elk that roam
in and out of the park,
representing a vital shift
of resources. The elk
provide food for predators
such as wolves, and their
own feeding affects soil
fertility, the diversity of
plants, and the behavior of
other grazers competing
for grass.